[ltt-dev] [BABELTRACE PATCH] Extract int and char arrays from fields

[mathieu.desnoyers@efficios.com (Mathieu Desnoyers)]

* Julien Desfossez (julien.desfossez at polymtl.ca) wrote:
> Three helper functions to ease the extraction of basic types from event
> fields. For now we support signed and unsigned integers and strings.
> Other functions could be added following the same principle for other
> types.

FYI, I already started cleaning up ctf.c using these functions.

Thanks!

Mathieu

> 
> Signed-off-by: Julien Desfossez <julien.desfossez at polymtl.ca>
> ---
>  include/babeltrace/types.h |    3 +++
>  types/array.c              |   27 +++++++++++++++++++++++++++
>  types/integer.c            |   30 ++++++++++++++++++++++++++++++
>  3 files changed, 60 insertions(+), 0 deletions(-)
> 
> diff --git a/include/babeltrace/types.h b/include/babeltrace/types.h
> index a9fb5fe..62a0d4f 100644
> --- a/include/babeltrace/types.h
> +++ b/include/babeltrace/types.h
> @@ -383,6 +383,8 @@ void definition_unref(struct definition *definition);
>  struct declaration_integer *integer_declaration_new(size_t len, int byte_order,
>  				  int signedness, size_t alignment,
>  				  int base, enum ctf_string_encoding encoding);
> +uint64_t get_unsigned_int(struct definition *field);
> +int64_t get_signed_int(struct definition *field);
>  
>  /*
>   * mantissa_len is the length of the number of bytes represented by the mantissa
> @@ -493,6 +495,7 @@ struct declaration_array *
>  uint64_t array_len(struct definition_array *array);
>  struct definition *array_index(struct definition_array *array, uint64_t i);
>  int array_rw(struct stream_pos *pos, struct definition *definition);
> +GString *get_char_array(struct definition *field);
>  
>  /*
>   * int_declaration and elem_declaration passed as parameter now belong
> diff --git a/types/array.c b/types/array.c
> index db6853f..87b2083 100644
> --- a/types/array.c
> +++ b/types/array.c
> @@ -205,3 +205,30 @@ struct definition *array_index(struct definition_array *array, uint64_t i)
>  		return NULL;
>  	return g_ptr_array_index(array->elems, i);
>  }
> +
> +GString *get_char_array(struct definition *field)
> +{
> +	struct definition_array *array_definition;
> +	struct declaration_array *array_declaration;
> +	struct declaration *elem;
> +
> +	array_definition = container_of(field, struct definition_array, p);
> +	array_declaration = array_definition->declaration;
> +	elem = array_declaration->elem;
> +	if (elem->id == CTF_TYPE_INTEGER) {
> +		struct declaration_integer *integer_declaration =
> +			container_of(elem, struct declaration_integer, p);
> +
> +		if (integer_declaration->encoding == CTF_STRING_UTF8
> +				|| integer_declaration->encoding == CTF_STRING_ASCII) {
> +
> +			if (integer_declaration->len == CHAR_BIT
> +					&& integer_declaration->p.alignment == CHAR_BIT) {
> +
> +				return array_definition->string;
> +			}
> +		}
> +	}
> +	fprintf(stderr, "[warning] Extracting string\n");
> +	return NULL;
> +}
> diff --git a/types/integer.c b/types/integer.c
> index e55c03e..9e6df58 100644
> --- a/types/integer.c
> +++ b/types/integer.c
> @@ -103,3 +103,33 @@ void _integer_definition_free(struct definition *definition)
>  	declaration_unref(integer->p.declaration);
>  	g_free(integer);
>  }
> +
> +uint64_t get_unsigned_int(struct definition *field)
> +{
> +	struct definition_integer *integer_definition;
> +	const struct declaration_integer *integer_declaration;
> +
> +	integer_definition = container_of(field, struct definition_integer, p);
> +	integer_declaration = integer_definition->declaration;
> +
> +	if (!integer_declaration->signedness) {
> +		return integer_definition->value._unsigned;
> +	}
> +	fprintf(stderr, "[warning] Extracting unsigned value in a signed int\n");
> +	return (uint64_t)integer_definition->value._signed;
> +}
> +
> +int64_t get_signed_int(struct definition *field)
> +{
> +	struct definition_integer *integer_definition;
> +	const struct declaration_integer *integer_declaration;
> +
> +	integer_definition = container_of(field, struct definition_integer, p);
> +	integer_declaration = integer_definition->declaration;
> +
> +	if (integer_declaration->signedness) {
> +		return integer_definition->value._signed;
> +	}
> +	fprintf(stderr, "[warning] Extracting signed value in an unsigned int\n");
> +	return (int64_t)integer_definition->value._unsigned;
> +}
> -- 
> 1.7.5.4
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com